from google.appengine.ext import ndb

class User(ndb.Model):
    _use_cache = False
    _use_memcache = False
    city = ndb.StringProperty()
    email = ndb.StringProperty()
    phone = ndb.StringProperty()

User(id='john1', city='London', email='john@doe.com', phone='1-800-JOHN').put()
User(id='jane1', city='London', email='jane@doe.com', phone='1-800-JANE').put()

for user in User.query(User.city == 'London'):
    print user.email
